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Biomedical subjects

C Schulze

Publications and source records attributed to C Schulze.

At least 91 records · Page 5Linked to original sources
PubMed1992

The interendothelial junction in myocardial capillaries: evidence for the existence of regularly spaced, cleft-spanning structures.

Water and hydrophilic solutes cross the endothelium of continuous capillaries via the paracellular cleft and possibly other routes. This pathway shows a selectivity to molecule size and charge. However, it is not yet known which systems confer this selectivity. Isolated rat hearts were perfusion-fixed through the coronary circulation, stained with lanthanum or tannic acid, and further processed for transmission electron microscopy. Thin sections viewed at x 160,000 magnification revealed regularly spaced, cleft-spanning structures in the wider zone of a small percentage of clefts in addition to at least one zonula occludens. Goniometric tilting of the specimen in steps of 5 degrees perpendicular to the plane of the wide zone showed that such "linkers" can be revealed in at least 40% of all clefts. They become visible at some tilt angles, although the same area of the cleft is featureless at other angles. Single linker spacing measurements were obtained using a computerized image analysis system, and compiled in a frequency distribution chart. On the basis of these data, two models of a regular linker distribution within the cleft are illustrated. Our results provide evidence for the presence of regularly spaced, cleft-spanning structures within the interendothelial cleft which may have implications for endothelial cell-cell adhesion and permeability.

Animals↗
PubMed1992

[Hospital care versus home nursing: on the quality of life of terminal tumor patients].

The present study investigated quality of life in 41 terminally ill cancer patients. Twenty-one of them received hospital care, 20 home-bound hospice care. These groups were comparable with respect to the patients' physical condition. The following variables were chosen as indicators of quality of life: perceived social support and social distress, coping with illness, perceived positive environmental factors, perceived control over daily activities and caring routines, contentedness with medical care and nursing, physical well-being. Assessment was made by means of a semi-structured interview. The data indicate that the home-bound care was superior with respect to the following variables: perceived positive environmental factors, perceived control over daily activities and caring routines, and contentedness with nursing. No differences between groups were found for any of the other variables.

Adult↗
PubMed1991

[Reactions to stress during the normal menstrual cycle].

In the present study, we questioned, whether the variability of physiological parameters within a menstrual cycle are connected with psychological variables like mood, state of health and positive/negative daily occurrences. We examined 20 women with normal cycles. The definition of a normal cycle was: 28 (+/- 5) days of length, standard weight according to Broca, 3-5 days menstrual bleeding, no oral contraceptive during the last 6 months, no IUP, inconspicuous hormones (no raised prolactin or testosterone levels), gynecologically unremarkable findings. Gynecological and psychological data were gathered daily during one menstrual cycle: hormone levels, vaginal ultrasound for detecting follicle growth, ovulation, corpus luteum and endometrial development. The psychological data on mood, state of health and positive/negative occurrences were recorded in parallel in the form of a diary, in which new entries were made daily. The results showed, that only 6 out of the 20 women had a normal menstrual cycle as defined above. Women with a normal (physiological) cycle, report in their diary: less negative bodily tendencies, more positive everyday situations, but the same amount of negative situations as women with noticeable cycles. Both the normal cycle group and the conspicuous cycle group report more negative body states and more negative moods in the premenstruum than the middle phase. The implications of these results are discussed.

Adult↗
PubMed1990

Concretions in the human testis are derived from the basal lamina of seminiferous cords.

We provide evidence that testicular concretions form exclusively in association with seminiferous cords. Testicular material obtained from 6 patients with various disorders of spermatogenesis was studied by means of light- and electron microscopy. Seminiferous cords in the testes examined form so-called hypoplastic zones. They contain immature Sertoli cells and are surrounded by an unusually thick basal lamina and one or two layers of myofibroblasts. They display extensive coiling and form ring-like structures. Concretions are located at the periphery or in the center of the cords and consist of a hyaline material with an occasional granular core. They are enveloped by Sertoli cells or myofibroblasts. Data presented indicate that concretions may develop within the above-mentioned ring-like structures or in deep indentations of the surrounding connective tissue. Computer-assisted 3-D reconstructions of a seminiferous cord based on 24 serial semithin sections revealed that the majority of concretions communicate with the interstitial tissue through a broad opening comparable to a "meso". On the basis of our observations we could demonstrate that concretions are accumulations of basal lamina that occasionally contain remnants of degenerated myofibroblasts. They form outside the cords and belong to the connective tissue compartment. As the components of the basal lamina are thought to be produced by the interaction of Sertoli cells and myofibroblasts we tentatively assume that the development of concretions reflects a disturbance in this complex interaction. We suggest that the presence of concretions refers to a developmental disorder and may be pathognomonic for the occurrence of defective seminiferous cords.

Adolescent↗
PubMed1990

New evidence for endoplasmic reticulum and Golgi apparatus in rabbit reticulocytes.

The incorporation of 14C-galactose and 14C-fucose in rabbit reticulocytes obtained by bleeding anaemia and separated according to their stage of maturation was studied. Only the youngest reticulocytes were shown to incorporate the two sugars with galactosylation being three times higher. The glycosylation behaved different from the synthesis of membrane proteins with respect to the dependence on temperature and time. Among the newly synthesized membrane proteins the signal sequence receptor (SSR), a compound of the system addressing protein translocation, was detected immunologically.

Animals↗
PubMed1989

Dysfunctional cognitions, attributional style, and depression in bulimia.

A group of 44 bulimic women (DSM-III) as well as 38 women with no indication of an eating disorder, comparable with respect to age, weight and height, were studied by means of the Beck Depression Inventory (BDI), the Dysfunctional Attitude Scale (DAS), the Attributional Style Questionnaire (ASQ), and an Eating Disorder Questionnaire (EDQ). Bulimics showed significantly higher BDI, DAS and ASQ (bad events) scores, respectively. In both groups BDI scores were significantly correlated with DAS and ASQ (bad events) results. BDI was highly predictive of severity of bulimia while no significant prediction was obtained from either DAS or ASQ (bad events) scores. The findings provide first evidence that dysfunctional attitudes and depressive attributional style are predominant in bulimic women but at the same time are not necessarily predictive of the severity of the disorder.

Adult↗
PubMed1989

The significance of alpha-fetoprotein and other tumour markers in differential immunocytochemistry of primary liver tumours.

One hundred benign and malignant primary liver tumours were screened immunocytochemically for alpha-fetoprotein (AFP), alpha 1-antitrypsin, alpha-human chorionic gonadotropin, carcinoembryonic antigen (CEA), keratin and vimentin. Alpha-fetoprotein was found in 16/63 (24%) hepatocellular carcinomas and in two hepatoblastomas. When comparing tissue positivity for AFP with tumour differentiation, grade 1 hepatocellular carcinomas were found to be negative, while 21% of grade 2, 36% of grade 3 and 16% of grade 4, respectively, stained positively. Alpha-fetoprotein positive cells were present in 9/10 hepatocellular carcinomas with serum levels exceeding 5000 ng/ml, but were absent in 17 tumours with serum AFP levels below 5000 ng/ml. All tumours other than hepatocellular carcinomas and hepatoblastomas were AFP negative. Carcinoembryonic antigen was present in 72% of cholangiocarcinomas, but was demonstrated in only one hepatocellular carcinoma. This exception was a combined hepatocellular-cholangiocarcinoma in which CEA expression was restricted to the cholangiocellular part. Alpha 1-antitrypsin was found in 4/63 hepatocellular carcinomas, in 2/2 fibrolamellar carcinomas and in 2/18 cholangiocarcinomas. Alpha-human chorionic gonadotropin was detected in one hepatocellular carcinoma and was strongly expressed in both fibrolamellar carcinomas. Weak staining for keratin was seen in most tumours with hepatocellular differentiation. All cholangiocarcinomas, in contrast, were strongly labelled with the keratin antibody. Co-expression of keratin and vimentin was observed in seven poorly differentiated hepatocellular carcinomas and three cholangiocarcinomas as well as in the two hepatoblastomas. The findings suggest that AFP is a diagnostic but rather insensitive immunocytochemical marker for hepatocellular differentiation in malignant liver tumours; CEA and keratin may help in discriminating cholangiocarcinomas from hepatocellular carcinomas.

Antigens, Neoplasm↗
PubMed1988

Response of the human testis to long-term estrogen treatment: morphology of Sertoli cells, Leydig cells and spermatogonial stem cells.

The present investigation is concerned with the morphological changes observed in human testicular tissue following prolonged estrogen administration. Testicular material obtained from 11 transsexual patients who had been submitted to long-term estrogen treatment prior to sex-reversal surgery was studied by means of light- and electron microscopy. The testes of all patients examined present a more or less uniform appearance: There are narrow seminiferous cords surrounded by an extensively thickened lamina propria. They contain Sertoli cells and spermatogonia exclusively. There is no evidence of typical Leydig cells. The persisting spermatogonia show the characteristic features of pale type-A spermatogonia, whereas dark type-A spermatogonia are almost completely eliminated from the epithelium. In view of the fact that spermatogonia that survived radiotherapy and treatment with various noxious agents have recently been regarded as the stem cells of the human testis, it is suggested that also the majority of those spermatogonial types that are less sensitive to disturbances of the endocrine balance may consist of stem cells. The present results, therefore, corroborate the concept that the stem cells of the human testis may be derived from pale type-A spermatogonia or the variants of this cell type. Sertoli cells display two types of ovoid nuclei. In contrast to untreated material the nuclei lie adjacent to the basal lamina, and organelles and telolysosomes are confined to the apical cytoplasm. The apico-basal differentiation of mature cells, therefore, is not observed. Moreover, typical organelles and inclusions of mature cells are absent, as are the junctional specializations. Thus, Sertoli cells have transformed into immature cells, resembling precursors prior to puberty. Fibroblast-like cells in the interstitial tissue, which display strongly lobulated nuclei, a well-developed smooth endoplasmic reticulum, lipid droplets, and numerous inclusions are assumed to represent dedifferentiated Leydig cells. Since after estrogen treatment serum testosterone and gonadotropin levels are known to be reduced, it appears that the morphological changes correlate well with the endocrine status.

Adult↗
PubMed1987

Comparison of induction of DNA single-strand breaks and initiation of rat hepatocarcinogenesis by different nitrosamines.

The capacities of nitrosamines to induce DNA single-strand breaks (SSB) and to initiate carcinogenesis in rat liver were compared. N-Nitrosodiethanolamine (NDELA), N-nitrosoethylhydroxyethylamine (NEHEA) and N-nitrosodiethylamine (NDEA) were equipotent in inducing DNA SSB when administered by gavage at doses of 0.35 mmol/kg, 0.015 mmol/kg and 0.37 mmol/kg, respectively. Male Wistar rats were injected with these nitrosamines and were then submitted to a selection procedure. Ten rats per group were sacrificed one week after the end of the selection to see the effects of the nitrosamines on the development of preneoplastic lesions. The numbers of gamma-glutamyl transferase (GGT)-positive lesions per cm2 were 0.8, 2.1, 5.2 and 40.1 in rats treated with saline, NDELA, NEHEA and NDEA, respectively. N-Nitrosobis(2,2,2-trifluorethyl)amine (6F-NDEA), a nongenotoxic and noncarcinogenic nitrosamine, induced 0.7 GGT-positive lesions per cm2. Ten rats per group also received 0.05% phenobarbital in their drinking-water and were killed six months after initiation in order to see the effect of the different nitrosamines on the incidence and yield of tumours. Two extrahepatic cancers were found after administration of NEHEA, whereas two hepatocellular carcinomas were detected after injection of NDEA. No cancer developed in the other groups. Although other factors may influence the process, these results indicate that no simple correlation can be established between induction of SSB in DNA and initiation of tumours by nitrosamines in rat liver.

Animals↗
PubMed1985

[The concept of disease in patients with atopic dermatitis].

34 former patients of a dermatological department with atopic dermatitis were compared with 29 patients of an Ear-Nose-Throat-department having similar age, sex and occupation and showing hardly any psychosomatic disturbances. Contrary to our expectations, the empiric-psychological examination did not reveal any impairment of the social behavior or the emotional competence of patients suffering from atopic dermatitis. In comparison to the control group, the patients of the dermatological department attached significantly greater importance to psychological influences on development as well as treatment of the disease. There was a correlation between symptoms "coming from outside" and the social competence; however, this correlation was not significantly greater than the control group. Our investigations suggest that atopic dermatitis may be differentiated into somatical-organizing types and rather psychological-organizing types. The second group shows uncertainties with regard to the social competence.

Age Factors↗